Volume 39,Issue 3,2011 Table of Contents
2011, 39(3):257-265.
Abstract:
Mesoscale convective systems are very important to Meiyu front heavy rainfall. It is of great significance for improving the forecast capability of Meiyu front heavy rainfall and researches on the structure, development, and physical mechanisms of mesoscale convective systems. In recent years, remarkable advances in the researches on this topic have been reported. A briefly comprehensive review for the advances in the researches on mesoscale convective systems is presented, which include the multiscale structure of Meiyu cloud systems, the development conditions and structures of mesoβ and mesoγ scale systems, the distribution and conversion characteristics of microphysics, and their feedback to dynamical and thermal processes, as well as some related issues.
Mesoscale convective systems are very important to Meiyu front heavy rainfall. It is of great significance for improving the forecast capability of Meiyu front heavy rainfall and researches on the structure, development, and physical mechanisms of mesoscale convective systems. In recent years, remarkable advances in the researches on this topic have been reported. A briefly comprehensive review for the advances in the researches on mesoscale convective systems is presented, which include the multiscale structure of Meiyu cloud systems, the development conditions and structures of mesoβ and mesoγ scale systems, the distribution and conversion characteristics of microphysics, and their feedback to dynamical and thermal processes, as well as some related issues.
2011, 39(3):266-271.
Abstract:
Based on the hourly infrared cloud images from the geostationary meteorological satellite (FY2) and the enhanced precipitation observation from the regional mesoscale surface automatic weather observation network, through the parameterization of cloud images, the relationship between cloud parameters and precipitation rate of different categories are analyzed by using the dynamical correlation method. The cloud parameters include the twoband combination of longwave infrared and splitwindow, the twoband combination of longwave infrared and water vapor, and brightness temperature, etc. Through the above analysis, a dynamical estimation model of precipitation nowcasting is built based on the optimal correlation between precipitation rate and related cloud parameters. The new estimation model was applied in real time to threehour precipitation forecast. The distribution of forecasted precipitation is similar to that from observation. The precipitation centers are roughly in agreement with the observed centers, but the estimated precipitation rates are lower than the observed in high mountain areas.
Based on the hourly infrared cloud images from the geostationary meteorological satellite (FY2) and the enhanced precipitation observation from the regional mesoscale surface automatic weather observation network, through the parameterization of cloud images, the relationship between cloud parameters and precipitation rate of different categories are analyzed by using the dynamical correlation method. The cloud parameters include the twoband combination of longwave infrared and splitwindow, the twoband combination of longwave infrared and water vapor, and brightness temperature, etc. Through the above analysis, a dynamical estimation model of precipitation nowcasting is built based on the optimal correlation between precipitation rate and related cloud parameters. The new estimation model was applied in real time to threehour precipitation forecast. The distribution of forecasted precipitation is similar to that from observation. The precipitation centers are roughly in agreement with the observed centers, but the estimated precipitation rates are lower than the observed in high mountain areas.
2011, 39(3):272-279.
Abstract:
With the NCEP/NCAR reanalysis data, the background conditions, under which 33 cases of convective merger occurred in the Jianghuai region during the summers of 2005 and 2006, are analyzed. It is shown that these circulation patterns for merging can be classified into five types: merging before a trough in North China, behind a trough in North China, inside a subtropical high pressure, outside a subtropical high pressure, and inside an east wind system. The dynamic and thermodynamic conditions triggering the five kinds of convective merging are different. In addition, the impact of the mountainous terrain on ground temperature and energy is closely related to the occurrence and merging of convective clouds.
With the NCEP/NCAR reanalysis data, the background conditions, under which 33 cases of convective merger occurred in the Jianghuai region during the summers of 2005 and 2006, are analyzed. It is shown that these circulation patterns for merging can be classified into five types: merging before a trough in North China, behind a trough in North China, inside a subtropical high pressure, outside a subtropical high pressure, and inside an east wind system. The dynamic and thermodynamic conditions triggering the five kinds of convective merging are different. In addition, the impact of the mountainous terrain on ground temperature and energy is closely related to the occurrence and merging of convective clouds.
2011, 39(3):280-288.
Abstract:
The temporal and spatial characteristics of cloud amount over China are analyzed by using ISCCP (International Satellite Cloud Climatology Project) monthly mean D2 data from July 1983 to June 2005. The results show that over the past 20 years, total cloud amount had little change in trend in most parts of China; there was an increasing trend in total cloud amount in South China and the northwestern China, while a decreasing trend in the central part of the QinghaiTibet Plateau. It is also found that the total cloud amount in different seasons had different trends.
The temporal and spatial characteristics of cloud amount over China are analyzed by using ISCCP (International Satellite Cloud Climatology Project) monthly mean D2 data from July 1983 to June 2005. The results show that over the past 20 years, total cloud amount had little change in trend in most parts of China; there was an increasing trend in total cloud amount in South China and the northwestern China, while a decreasing trend in the central part of the QinghaiTibet Plateau. It is also found that the total cloud amount in different seasons had different trends.
2011, 39(3):289-294.
Abstract:
With the methods of rotary EOF analysis, composition analysis, wavelet, and trend analysis， the spatialtemporal variations of thunderstorms are analyzed for 38 stations over the Xizang region from 1979 to 2008．The research results show that thunderstorms happen mainly after noon， and their durations are usually less than 20 minutes．There is quasi15year variation in the average total number of thunderstorms． Since 2000，the total number of thunderstorms has showed a more obvious decreasing tendency． The interval between the first and last thunderstorm days became shorter and shorter, but the differentia existed in different regions．The further analysis shows the interval between the first and last thunderstorm days became longer in the northwestern Changdu and the central Naqu and shorter in the other regions．
With the methods of rotary EOF analysis, composition analysis, wavelet, and trend analysis， the spatialtemporal variations of thunderstorms are analyzed for 38 stations over the Xizang region from 1979 to 2008．The research results show that thunderstorms happen mainly after noon， and their durations are usually less than 20 minutes．There is quasi15year variation in the average total number of thunderstorms． Since 2000，the total number of thunderstorms has showed a more obvious decreasing tendency． The interval between the first and last thunderstorm days became shorter and shorter, but the differentia existed in different regions．The further analysis shows the interval between the first and last thunderstorm days became longer in the northwestern Changdu and the central Naqu and shorter in the other regions．
2011, 39(3):295-301.
Abstract:
A severe snowstorm occurred between 9 and 12 November 2009 in Shanxi Province, which was the strongest snowstorm since meteorological records began. The snowfall in most parts of the province was in the range of 10 to 66 mm, and that at 86 counties (cities) reached the maximum for the same period in history. Both upperand lowerlevel meteorological observation data and satellite images were used in the comprehensive analysis of the process. The results show: the strong southwest flow at upper levels, the northeast air at lower levels, and the returnflow on the surface provided jointly a favorable circulation condition for this snowstorm. The 500 hPa trough and 700 hPa shear line were the major influencing systems. The continued moisture convergence from the lowlevel jet provided sufficient water vapor. In satellite images, the lowvalue areas with TBB being lower than -50 ℃ and the heavy snow fall areas had a good correspondence relationship.
A severe snowstorm occurred between 9 and 12 November 2009 in Shanxi Province, which was the strongest snowstorm since meteorological records began. The snowfall in most parts of the province was in the range of 10 to 66 mm, and that at 86 counties (cities) reached the maximum for the same period in history. Both upperand lowerlevel meteorological observation data and satellite images were used in the comprehensive analysis of the process. The results show: the strong southwest flow at upper levels, the northeast air at lower levels, and the returnflow on the surface provided jointly a favorable circulation condition for this snowstorm. The 500 hPa trough and 700 hPa shear line were the major influencing systems. The continued moisture convergence from the lowlevel jet provided sufficient water vapor. In satellite images, the lowvalue areas with TBB being lower than -50 ℃ and the heavy snow fall areas had a good correspondence relationship.
2011, 39(3):302-307.
Abstract:
By using conventional meteorological, satellite, radar, regional automatic weather station, and NCEP reanalysis data, the characteristics of precipitation over the northeastern Fujian Province induced by the typhoon Morakot are studied. The results show that Morakot had an obvious hollow structure; the favorable environmental condition, the continuous impact of convective cells in the spiral cloud band, and the slow movement of the typhoon were the main reasons for the heavy rainfall, while the increasing role of topography was also evident. Through comparing the intensity of basic reflectivity factor and the hourtohour rainfall of regional automatic weather stations, the precipitation rate features of convective cells in the spiral cloud band are discussed, which is of reference value for the shortterm and nowcasting forecast of typhoon heavy rainfall.
By using conventional meteorological, satellite, radar, regional automatic weather station, and NCEP reanalysis data, the characteristics of precipitation over the northeastern Fujian Province induced by the typhoon Morakot are studied. The results show that Morakot had an obvious hollow structure; the favorable environmental condition, the continuous impact of convective cells in the spiral cloud band, and the slow movement of the typhoon were the main reasons for the heavy rainfall, while the increasing role of topography was also evident. Through comparing the intensity of basic reflectivity factor and the hourtohour rainfall of regional automatic weather stations, the precipitation rate features of convective cells in the spiral cloud band are discussed, which is of reference value for the shortterm and nowcasting forecast of typhoon heavy rainfall.
2011, 39(3):308-314.
Abstract:
A heavy rainfall event occurred over the south coast of Zhejiang Province from 29 September to 1 October 2009, caused by an easterly wave, is studied with the conventional meteorological data, mesoscale automatic weather station data, and 1°×1° reanalyzed NCEP data. The results show that the outer circumfluence of the Typhoon Ketsana provided disturbance for the easterly wave; the lowerlevel southeast jet, induced by the enhancement of the subtropical anticyclone over the western Pacific, transported a plenty of moisture for the storm; the weak cool air strengthened the precipitation. The diagnostic analysis of physical quantities based on the NCEP reanalysis data indicates that the easterly wave happened at lower levels and caused a mesoscale low vortex in the latter period. The vorticity and helicity at 850 hPa can reflect the evolution of the easterly wave and the mesoscale low vortex perfectly, as well as the areas of strong precipitation. The moisture flux divergence at 850 hPa indicates that the southeast jet provided enough moisture for the storm.
A heavy rainfall event occurred over the south coast of Zhejiang Province from 29 September to 1 October 2009, caused by an easterly wave, is studied with the conventional meteorological data, mesoscale automatic weather station data, and 1°×1° reanalyzed NCEP data. The results show that the outer circumfluence of the Typhoon Ketsana provided disturbance for the easterly wave; the lowerlevel southeast jet, induced by the enhancement of the subtropical anticyclone over the western Pacific, transported a plenty of moisture for the storm; the weak cool air strengthened the precipitation. The diagnostic analysis of physical quantities based on the NCEP reanalysis data indicates that the easterly wave happened at lower levels and caused a mesoscale low vortex in the latter period. The vorticity and helicity at 850 hPa can reflect the evolution of the easterly wave and the mesoscale low vortex perfectly, as well as the areas of strong precipitation. The moisture flux divergence at 850 hPa indicates that the southeast jet provided enough moisture for the storm.
2011, 39(3):315-319.
Abstract:
Depend on the working principles of wind profiling radar and application practice, the sounding altitude, spatial and temporal resolution, and measurement errors of the tropospheric wind profiling radar are calculated, and the data availability is analyzed．The results show: through selecting suitable operating waveforms and modes, the radar detection altitude can range from 150 to 12000 meters, and height resolution can be up to 75 m, temporal resolution to 10 minute, wind speed accuracy to 1 m/s, wind direction to 10°, and data availability to over 80%. The conclusions can be used as references for the regional networking of wind profiling radar.
Depend on the working principles of wind profiling radar and application practice, the sounding altitude, spatial and temporal resolution, and measurement errors of the tropospheric wind profiling radar are calculated, and the data availability is analyzed．The results show: through selecting suitable operating waveforms and modes, the radar detection altitude can range from 150 to 12000 meters, and height resolution can be up to 75 m, temporal resolution to 10 minute, wind speed accuracy to 1 m/s, wind direction to 10°, and data availability to over 80%. The conclusions can be used as references for the regional networking of wind profiling radar.
2011, 39(3):320-325.
Abstract:
The technical characteristics and fault diagnosis methods of he CINRAD/SB radar receiving system are summarized in detail, according to the signal flows of the main channel, the testchannel, and fault location channel, from the aspects of monitoring and alarm information, and parameters measured at key points. Three fault diagnosis methods are introduced: using RDA computer alarm information directly, testing keypoint waveform, and according to the testing channel. Three typical examples of finding faults (the frontend, backend and test channels of the main channel receiver) and the corresponding solutions are given, and some suggestions on the maintenance of CINRAD/SB radar are presented.
The technical characteristics and fault diagnosis methods of he CINRAD/SB radar receiving system are summarized in detail, according to the signal flows of the main channel, the testchannel, and fault location channel, from the aspects of monitoring and alarm information, and parameters measured at key points. Three fault diagnosis methods are introduced: using RDA computer alarm information directly, testing keypoint waveform, and according to the testing channel. Three typical examples of finding faults (the frontend, backend and test channels of the main channel receiver) and the corresponding solutions are given, and some suggestions on the maintenance of CINRAD/SB radar are presented.
2011, 39(3):326-331.
Abstract:
The weather situation and the principles of snowfall estimation by using of Doppler radar data are introduced. The snowfall of a snowstorm weather process occurred in Shijiazhuang city from 10 to 12 November 2009 is computed based on the products of Doppler radar and the intensive snowfall observation by means of the Kalman filter method. The results indicate: (1) To use the Kalman filter method to estimate snowfall in this case is applicable, and the results are satisfactory, especially for the heavy snow of over 2 mm per hour. (2) The selection of elevations in estimating snowfall using the Kalman filter is based on the geographical features, the products of the radar reflectivity factor and echo tops, which is different from rainfall estimation. Both products of Doppler radar data and intensive snowfall observation data are useful in estimating the distribution of snowfall.
The weather situation and the principles of snowfall estimation by using of Doppler radar data are introduced. The snowfall of a snowstorm weather process occurred in Shijiazhuang city from 10 to 12 November 2009 is computed based on the products of Doppler radar and the intensive snowfall observation by means of the Kalman filter method. The results indicate: (1) To use the Kalman filter method to estimate snowfall in this case is applicable, and the results are satisfactory, especially for the heavy snow of over 2 mm per hour. (2) The selection of elevations in estimating snowfall using the Kalman filter is based on the geographical features, the products of the radar reflectivity factor and echo tops, which is different from rainfall estimation. Both products of Doppler radar data and intensive snowfall observation data are useful in estimating the distribution of snowfall.
2011, 39(3):332-338.
Abstract:
Using the infrared channel images detected by the FY2 meteorological satellite, the research on the detecting and tracking of cloud systems is conducted. The whole life cycle, including forming, developing， and dissipating, are studied based on the method of adaptive threshold temperature. The splitting and merging of cloud systems are tackled based on the geographical overlapping of two consecutive infrared images, and some characteristic quantities such as threshold temperature, area, moving velocity, temperature, temperature gradient and so on are extracted, in order to analyze the cloud evolution. An experiment on the identifying and tracking of the squall process occurred on June 2009 in Henan and Anhui is carried out and the evolutionary characteristics of the cloud systems during the whole life cycle are analyzed.
Using the infrared channel images detected by the FY2 meteorological satellite, the research on the detecting and tracking of cloud systems is conducted. The whole life cycle, including forming, developing， and dissipating, are studied based on the method of adaptive threshold temperature. The splitting and merging of cloud systems are tackled based on the geographical overlapping of two consecutive infrared images, and some characteristic quantities such as threshold temperature, area, moving velocity, temperature, temperature gradient and so on are extracted, in order to analyze the cloud evolution. An experiment on the identifying and tracking of the squall process occurred on June 2009 in Henan and Anhui is carried out and the evolutionary characteristics of the cloud systems during the whole life cycle are analyzed.
2011, 39(3):339-343.
Abstract:
In order to gear to the international practice of atmospheric motion vector BUFR encoding and to meet the requirements of international communication of meteorological satellite products, the BUFR encoding software of atmospheric motion vector data with the new WMO template is developed. In the encoding practice, the AMV quality control information is added by the associated field; the descriptors in one BUFR data subset are greatly increased from 18 to 254; and the information provided by the new template BUFR message is greatly enriched. The encoding results are shown that the length of the noncompressed BUFR message is 9 times bigger than that of the compressed one. For the convenience of GTS transformation, the compressed BUFR encoding is recommended, which has higher data compression ratio (about 53%) and is suitable for data transmission.
In order to gear to the international practice of atmospheric motion vector BUFR encoding and to meet the requirements of international communication of meteorological satellite products, the BUFR encoding software of atmospheric motion vector data with the new WMO template is developed. In the encoding practice, the AMV quality control information is added by the associated field; the descriptors in one BUFR data subset are greatly increased from 18 to 254; and the information provided by the new template BUFR message is greatly enriched. The encoding results are shown that the length of the noncompressed BUFR message is 9 times bigger than that of the compressed one. For the convenience of GTS transformation, the compressed BUFR encoding is recommended, which has higher data compression ratio (about 53%) and is suitable for data transmission.
2011, 39(3):344-347.
Abstract:
Through VB programming, a realtime transmission and quality control software of surface weather observation data from automatic weather stations is developed to replace the communications networking interface software. It can not only solve the problem of communication software termination when the backup dialup fails, but also review the elements of realtime observations. In case of abnormal transmission and data, the system dials through a modem to set mobile phone alarm, timely reminding the operator on duty. It is compatible with the networking and communications interface software, and if there is no file transferred within the first six minutes, it will launch the network communications interface software automatically. The application of the software in automatic weather stations can greatly reduce the abnormal and missing observations, and improve the timely transfer rate of meteorological data.
Through VB programming, a realtime transmission and quality control software of surface weather observation data from automatic weather stations is developed to replace the communications networking interface software. It can not only solve the problem of communication software termination when the backup dialup fails, but also review the elements of realtime observations. In case of abnormal transmission and data, the system dials through a modem to set mobile phone alarm, timely reminding the operator on duty. It is compatible with the networking and communications interface software, and if there is no file transferred within the first six minutes, it will launch the network communications interface software automatically. The application of the software in automatic weather stations can greatly reduce the abnormal and missing observations, and improve the timely transfer rate of meteorological data.
2011, 39(3):348-351.
Abstract:
On the basis of daily ground temperature observation, the analysis of characteristics of abnormal data, data processing methods, and the influences of improper maintenance of the ground temperature observations field on data quality are analyzed. The results show that the increased and unstable discrepancies between the data from automatic weather station and manual observation are caused by the abnormal sensor performance. The treatment of the abnormal data in the monthly report database should be conducted according to the actual situation. The differences of soil heterogeneous properties in groundtemperature observation field, the placement of thermometers, and the changes of the surrounding environment all can bring about the errors of the qualitycontrolled data, which needs close attention of weather observers.
On the basis of daily ground temperature observation, the analysis of characteristics of abnormal data, data processing methods, and the influences of improper maintenance of the ground temperature observations field on data quality are analyzed. The results show that the increased and unstable discrepancies between the data from automatic weather station and manual observation are caused by the abnormal sensor performance. The treatment of the abnormal data in the monthly report database should be conducted according to the actual situation. The differences of soil heterogeneous properties in groundtemperature observation field, the placement of thermometers, and the changes of the surrounding environment all can bring about the errors of the qualitycontrolled data, which needs close attention of weather observers.
2011, 39(3):352-355.
Abstract:
The agrometeorological observing and reporting software AgMODOS has been applied over the whole nation operationally. There exist great differences in understanding and implementation of Criterions for Agriculture Meteorological Observation between various provinces and regions, which results in obstacles in use of the system. Concerning the operational application of the system, some suggestions are presented about the observing, recording, and especially inputting, which can be used as references for agrometeorological observers over the country
The agrometeorological observing and reporting software AgMODOS has been applied over the whole nation operationally. There exist great differences in understanding and implementation of Criterions for Agriculture Meteorological Observation between various provinces and regions, which results in obstacles in use of the system. Concerning the operational application of the system, some suggestions are presented about the observing, recording, and especially inputting, which can be used as references for agrometeorological observers over the country
2011, 39(3):356-359.
Abstract:
A new detection system for ultraviolet rays is introduced. The system is composed of five parts: ultraviolet ray sensors, A/D data acquisition module, data processing module, DZZ12 management center, and computer monitoring center. With the high precision and high stablebility detection sensors, the radiation intensities of UVA and UVB are measured and sent to the A/D module in a voltage signal way. The data process module is in charge of intensity calculation and data statistics according to the meteorological standards. The system has good expansibility and compatibility, and the DZZ12 management center can handle several data process modules. It is convenient to set the local parameters with the soft keyboard and LCD screen. The computer monitoring center has the capability of remote data acquisition and remote control of the DZZ12 management center. The operating procedures of the system are described, and the data analysis results are presented.
A new detection system for ultraviolet rays is introduced. The system is composed of five parts: ultraviolet ray sensors, A/D data acquisition module, data processing module, DZZ12 management center, and computer monitoring center. With the high precision and high stablebility detection sensors, the radiation intensities of UVA and UVB are measured and sent to the A/D module in a voltage signal way. The data process module is in charge of intensity calculation and data statistics according to the meteorological standards. The system has good expansibility and compatibility, and the DZZ12 management center can handle several data process modules. It is convenient to set the local parameters with the soft keyboard and LCD screen. The computer monitoring center has the capability of remote data acquisition and remote control of the DZZ12 management center. The operating procedures of the system are described, and the data analysis results are presented.
2011, 39(3):360-362.
Abstract:
The design and implementation technology of remote control and management for unmanned weather radar are introduced and the monitoring methods of radar hardware and software systems are discussed in detail. The system can realize the remote realtime online monitoring of radar working state，and short messages are sent in accordance with the monitoring information, and software faults are handled through the remote desktop. The efficiency and data transmission quality of radar are improved obviously，and the automatic monitoring of weather radar status is realized.
The design and implementation technology of remote control and management for unmanned weather radar are introduced and the monitoring methods of radar hardware and software systems are discussed in detail. The system can realize the remote realtime online monitoring of radar working state，and short messages are sent in accordance with the monitoring information, and software faults are handled through the remote desktop. The efficiency and data transmission quality of radar are improved obviously，and the automatic monitoring of weather radar status is realized.
2011, 39(3):363-368.
Abstract:
Based on the data of turbulence flux observed by the eddcovariance method from 10 February to 20 September 2008 at the Shouxian National Climate Observatory, the WPL (WebbPearmanLeuning) and Liu methods are used to correct the latent heat flux and CO2 flux. The differences between the two methods and the influence of the correction methods on flux measurement are contrasted. The main results indicate that both methods can avoid effectively the false messages resulted from calculation and increase the precision of the measurements. The latent heat flux increased about 3% to 5%, and the CO2 flux decreased about 1% to 2% after correction. The correctional range of the WPL method is bigger than that of the Liu method.
Based on the data of turbulence flux observed by the eddcovariance method from 10 February to 20 September 2008 at the Shouxian National Climate Observatory, the WPL (WebbPearmanLeuning) and Liu methods are used to correct the latent heat flux and CO2 flux. The differences between the two methods and the influence of the correction methods on flux measurement are contrasted. The main results indicate that both methods can avoid effectively the false messages resulted from calculation and increase the precision of the measurements. The latent heat flux increased about 3% to 5%, and the CO2 flux decreased about 1% to 2% after correction. The correctional range of the WPL method is bigger than that of the Liu method.
2011, 39(3):369-373.
Abstract:
By use of DPS statistics, regression analysis, and other methods, an analysis is made of the herbage yield changes in the recent 10 years in five sites over the Qinghai Plateau (Henan, Gande, Qumalai, Haibei, and Xinghai) and the relationship between meteorological factors and herbage yields. The simulation results show that: Over the past 10 years, the highest annual herbage production was in Henan, an overall downward trend in Gande, and overall upward trend in Qumalai, Haibei,and Xinghai. In May, the variation amplitude of forage yields was the greatest at Xinghai and least at Haibei in five sites. From June to August, the variation amplitude of forage yields was the greatest at Qumalai, and least at Haibe. In August, during the formation stage of forage yields, there was abundant sunshine and ample rainfall, but the temperature was not high enough in Gande, Qumalai, Haibei, and Xinghai. In Henan, there was negative correlation between light and temperature during the growing season. A good fitting model of meteorological factors and the annual forage yields of the five sites is obtained, with the significance level being greater than 0.01, and the fitting results can be used as references for local livestock farming services.
By use of DPS statistics, regression analysis, and other methods, an analysis is made of the herbage yield changes in the recent 10 years in five sites over the Qinghai Plateau (Henan, Gande, Qumalai, Haibei, and Xinghai) and the relationship between meteorological factors and herbage yields. The simulation results show that: Over the past 10 years, the highest annual herbage production was in Henan, an overall downward trend in Gande, and overall upward trend in Qumalai, Haibei,and Xinghai. In May, the variation amplitude of forage yields was the greatest at Xinghai and least at Haibei in five sites. From June to August, the variation amplitude of forage yields was the greatest at Qumalai, and least at Haibe. In August, during the formation stage of forage yields, there was abundant sunshine and ample rainfall, but the temperature was not high enough in Gande, Qumalai, Haibei, and Xinghai. In Henan, there was negative correlation between light and temperature during the growing season. A good fitting model of meteorological factors and the annual forage yields of the five sites is obtained, with the significance level being greater than 0.01, and the fitting results can be used as references for local livestock farming services.
2011, 39(3):374-378.
Abstract:
A phased low temperature occurred in the summer of 2009 in Heilongjiang Province, resulting in a steriletype rice cool injury, during which the field crops had varying degrees of delayedtype cool injury and fertility postponement. Through calculating the daily cool accumulated temperature according to its relationship with the rice emptygrain rate and the probability distribution of the number of sensitive rice groups during sensitive periods, the rice emptygrain rates and loss rates caused by the steriletype rice cold injury are assessed by means of the daytoday and hourtohour mean temperature from June to August 2009. On the basis of the clear physiological responses of rice to low temperature and cool injury, the assessment method is described, from the view of the dynamic temporal changes of rice during sensitive stages, which is superior to the assessment methods of adopting average temperature or temperature anomaly as indicators and can improve the precision and quantification of assessment.
A phased low temperature occurred in the summer of 2009 in Heilongjiang Province, resulting in a steriletype rice cool injury, during which the field crops had varying degrees of delayedtype cool injury and fertility postponement. Through calculating the daily cool accumulated temperature according to its relationship with the rice emptygrain rate and the probability distribution of the number of sensitive rice groups during sensitive periods, the rice emptygrain rates and loss rates caused by the steriletype rice cold injury are assessed by means of the daytoday and hourtohour mean temperature from June to August 2009. On the basis of the clear physiological responses of rice to low temperature and cool injury, the assessment method is described, from the view of the dynamic temporal changes of rice during sensitive stages, which is superior to the assessment methods of adopting average temperature or temperature anomaly as indicators and can improve the precision and quantification of assessment.
2011, 39(3):379-384.
Abstract:
An introduction is made to the design, development, and core technology of the weatherbased graded wheat scab forecasting system based on Geographic Information System, taking Jiangsu Province as an example. The system uses VB.Net 2005 and ArcEngine as a development platform, based on MSSQL SERVER 2005 database query, using such three meteorological factors as daily average relative humidity, daily mean temperature, and the daily sunshine hours. Two algorithms are used to calculate meteorological grades for wheat scab occurrence and development, and text and graphics products containing geographic information are generated, so to achieve the capability of forecasting wheat scab. The system has the characteristics of powerful capability, efficient algorithm, and simple operation, with good potentials in application.
An introduction is made to the design, development, and core technology of the weatherbased graded wheat scab forecasting system based on Geographic Information System, taking Jiangsu Province as an example. The system uses VB.Net 2005 and ArcEngine as a development platform, based on MSSQL SERVER 2005 database query, using such three meteorological factors as daily average relative humidity, daily mean temperature, and the daily sunshine hours. Two algorithms are used to calculate meteorological grades for wheat scab occurrence and development, and text and graphics products containing geographic information are generated, so to achieve the capability of forecasting wheat scab. The system has the characteristics of powerful capability, efficient algorithm, and simple operation, with good potentials in application.
External LinksChina Meteorological AdministrationCMA Meteorological Observation CentreChinese Academy of Meteorological SciencesBeijing Meteorological ServiceNational Satellite Meteorological Center
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Supported by:Beijing E-Tiller Technology Development Co., Ltd.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.